Method of making an improved windshield antenna system

ABSTRACT

A windshield antenna system includes a first sheet of glass, a second sheet of glass and an interlayer of resinuous material bonding the two glass sheets together. A pair of antenna wires are adhered to the interlayer for most of their length. However, the antenna wires do have free ends projecting outwardly from between the bonded glass sheets at a cutout portion of the second glass sheet. A terminal having a first end portion defining a projecting neck, a main body portion and a second end portion defining a connector tip is formed from a conductive material. At least the body portion of the terminal is bonded to the exposed surface of the second glass sheet with the portion of the terminal defining the projecting neck extending to a position which is located over the cutout portion of the second glass sheet. The free ends of the antenna wires are wrapped around the projecting neck of the terminal. The wrapped wires and the projecting neck of the terminal are deformed into the space provided by the cutout portion of the second glass sheet. An electrical junction of high quality is formed between the wrapped antenna wires and the terminal by applying solder thereto. Any extraneous antenna wire is cut off. The space into which the projecting neck of the terminal and the wrapped antenna wires are deformed is sealed by a sealing material. The main body portion of the terminal is also sealed by a sealing material.

Unite States Patent Inventors Richard T. Dickason Birmingham; John A.Richardson, Harper Woods, both of Mich. [21] Appl. No. 9,814 [22] FiledFeb. 9, 1970 [45] Patented Oct. 26, 1971 [73] Assignee Ford MotorCompany Dearborn, Mich.

[54] METHOD OF MAKING AN IMPROVED WINDSHIELD ANTENNA SYSTEM 5 Claims, 5Drawing Figs. [52] US. Cl 156/105, 156/106,156/107, 343/712, 343/873[51] Int. CL C03c 27/12 [50] Field of Search 156/99-107, 275, 309, 267,250; 343/712, 711,

713, 873, 720 [56] References Cited UNITED STATES PATENTS 3,208,0709/1965 Boicey 343/712 3,484,583 12/1969 Shaw, Jr. 343/712 UX 3,543,272 11 /1970 Zawodniak 343/720 X Primary Examiner-Carl D. Quai'forthAssistant Examiner- Harvey E. Behrend Attorneys-John R. Faulkner andWilliam E. Johnson ABSTRACT: A windshield antenna system includes afirst sheet of glass, a second sheet of glass and an interlayer ofresinuous material bonding the two glass sheets together. A pair ofantenna wires are adhered to the interlayer for most of their length.However, the antenna wires do have free ends projecting outwardly frombetween the bonded glass sheets at a cutout portion of the second glasssheet. A terminal having a first end portion defining a projecting neck,a main body portion and a second end portion defining a connector tip isformed from a conductive material. At least the body portion of theterminal is bonded to the exposed surface of the second glass sheet withthe portion of the terminal defining the projecting neck extending to aposition which is located over the cutout portion of the second glasssheet. The free ends of the antenna wires are wrapped around theprojecting neck of the terminal. The wrapped wires and the projectingneck of the terminal are deformed into the space provided by the cutoutportion of the second glass sheet. An electrical junction of highquality is formed between the wrapped antenna wires and the terminal byapplying solder thereto. Any extraneous antenna wire is cutoff. Thespace into which the projecting neck of the terminal and the wrappedantenna wires are deformed is sealed by a sealing material. The mainbody portion of the terminal is also sealed by a sealing material.

METHOD OF MAKING AN IMPROVED WINDSI-IIELD ANTENNA SYSTEM BACKGROUND OFTHE INVENTION ln the recent past, windshield antenna systems have beenintroduced for use in conjunction with the radio receivers mountedwithin automotive vehicles. More particularly, the antenna for a radiois placed in a resinous interlayer which laminatestogether the sheets ofglass utilized for forming the windshield of the vehicle. ln general,the antenna system is fonned by apainof fine wires which are positionedfor a portion oftheir length in a central portion of the glass, Thewires extend from the base of the windshield upwardly to a point nearthe top of the windshield. The wires then extend outwardly along twodiverging legs to termination points near the top side edges of thewindshield. The antenna wires, in order not to impair visibility throughthe windshield and detract from the appearance of the vehicle, areformed from wire of a very fine diameter. Since the fine diameter wireis used for the antenna system, the manner in which the antenna wire isterminated to an electrical lead which may be connected, in turn, to theradio receiver is of great importance. The tennination is important sothat during the installation and utilization of the windshield antenna,substantial stress loads are not applied to the termination point of theantenna wires. Since these wires are of a fine diameter, any substantialload applied to their junction point would cause a rupture of thetermination and thus an interruption in the use of the antenna system.

The method disclosed in this application has been designed for use interminating fine antenna wires thereby to form a windshield antennasystem. The method has been designed to eliminate some of the problemsof the prior art in rapidly and efiiciently forming a terminationstructure of high quality. More particularly, the termination structureformed in accordance with the method of this invention is one whereinsubstantial stress loads are not applied to the termination of the fineantenna wires to a conductive terminal, but rather are applied by theconductive terminal to the glass sheet upon which the terminal ismounted.

SUMMARY OF THE INVENTION "glass having a cutout portion overlying thefirst sheet of glass,

an interlayer of resinous material bonding the two sheets of glasstogether in an assembled condition, and a pair of antenna wires adheredto the interlayer between the glass sheets, The antenna wires extendupwardly in the central portion of the windshield from the lower edgethereof and then outwardly along diverging leg portions which extend inopposite directions across the top of the windshield. The antenna wires,at their free or lower ends, extend outwardly from between the two glasssheets at the cutout portion of the second glass sheet.

ln accordance with the method of this invention for forming thewindshield antenna system, a conductive terminal is formed so as to havea body portion, a first end portion defining a projecting neck and asecond end portion defining a connector tip. Once the terminal isformed, at least the body portion of the terminal is bonded to theexposed surface of the second glass sheet in such a manner that thefirst end portion of the terminal defining the projecting neck extendsto a position which is located over the cutout portion of the secondglass sheet. The free ends of the antenna wires are wrapped about thefirst end portion of the terminal. The wrapped wires and the projectingneck of the terminal are deformed into the space provided by the cutoutportion of the second glass sheet. An electrical junction of highquality is formed between the wrapped antenna wires and the terminals bysoldering the junction therebetween, Any extraneous antenna wireremaining is cut off and discarded.

In greater detail, the space into which the projecting neck of theterminal and the wrapped antenna wires are located after being deformedis sealed by a sealing material. Similarly the main body portion of theterminal may be sealed by a sealing material if desired. Also, thesecond end of the terminal defining the connector tip is bent away fromthe plane of the main body portion of the tenninal in adirection awayfrom the exposed surface of the second glass sheet to facilitate theterminals connection by proper electrical leads to the radio receiver ofthe automotive vehicle.

In still greater detail, the bondingof the terminal to the glass sheethaving the cutout portion is accomplished in the following manner. Apiece of the material utilized to form the resinous interlayer betweenthe two glass sheets is fitted between the glass sheet having the cutoutportion and the main body portion of the terminal. The terminal isclamped to the glass sheets and, thereafter, the glass-sheets and theterminal are subjected to an autoclaving operation wherein the heat andpressure are applied to bond the tenninal to the glass sheets. Thisautoclaving step may be carried out simultaneously with the autoclavingstep utilized to laminate the first and second glass sheets together.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing aportion of the windshield antenna system manufactured by the improvedmethod of this invention. FIG. 2 is a cross-sectional view showinggreater details of the structure of HG. 1. FIG. 3 is anothercross-sectional view showing the antenna system manufactured by theimproved method of thisinvention installed in an automotive vehicle.FIG. 4 is an isometric view of a conductive terminal which may beutilized in constructing the windshield antenna system. FIG. 5 is aschematic view of a windshield having an antenna system located therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention relates to methodof manufacturing a windshield antenna system and, more particularly, toa method of manufacturing a windshield antenna system which has animproved termination structure for the fine wires utilized as theantenna in such a system. The windshield antenna system is shown inFIGS. 1 and 5 and is generally designated by the numeral 10.

The following basic parts are first assembled by the proper methodologyin order to form the windshield antenna system 10. A first sheet ofglass 12 and a second sheet of glass 14 are laminated together byutilization of a resinous material such as a polyvinyl butyralinterlayer 16 in a normal laminating operation (best seen in FIGS. 2 and3). The normal laminating operation consists of positioning theinterlayer between the two glass sheets, thereafter applying pressure tothe two glass sheets to temporarily bind them to the vinyl interlayer,and finally, autoclavingthe two glass sheets with the interposed vinylinterlayer. In the autoclaving step, the Windshields are immersed in ahot oil bath and the bath is heated and pressure applied thereto, Duringthis autoclaving step, the vinyl interlayer cures and bonds the twoglass sheets together in order to form a windshield assembly.

The second glass sheet has a cutout portion 18 formed therein at thecentral portion of its lower edge for the purpose of exposing the endsof a pair of fine antenna wires 20-20. These fine antenna wires, forexample may have a diameter of approximately 00054-00056 inch and beformed of copper having a resistance of approximately 4l5 ohms per 1,000feet. The cutout portion 18 may, if desired, be a drill hole through theglass.

As may be best seen in FIG. 5, the antenna wires 20 extend upwardly fromthe cutout portion 18 of the second glass sheet 14 to a point at whichthe ends of the wires, laminated between the glass sheets 12 and 14,extend parallel to the base of the glass sheets. The length dimension ofthe antenna wires in the direction parallel to the base of the glasssheets is one of the principal controlling factors in the receptioncharacteristics of the antenna. As indicated in FIG. 5, the outwardlyturned ends of the antenna wires 20-20 are generally laid in a portionof the windshield wherein the gradient band 22 (indicated by dashedlines at its lower end) is positioned. The gradient band is dark incolor and it reduces the amount of light energy which passes through theupper portion of the windshield. Also, because the gradient band is thedarkest portion of the windshield, the extending legs of the antenna arenot easily seen from either side of the windshield.

The antenna wires 20- 20 are preferably adhered to the resinousinterlayer 16 in an initial processing operation. Such adherance may beaccomplished by laying the antenna wires out in a prescribed pattern onthe interlayer and thereafter ironing the wires to heat themsufficiently so that they become bonded to the interlayer. Thereafterthe interlayer containing the wires is placed between the first glasssheet 12 and the second glass sheet 14 and heat and pressure are appliedthereto so that the two glass sheets are laminated into the windshield.Prior to such laminating operation, the free ends of the antenna wires,which extend out beyond the cutout portion 18 of the second glass sheet14 are bent up and laid over the second glass sheet so that the freeends thereof do not become adhered to the resinous material during theautoclaving step of the laminating operation.

In accordance with the teachings of the method of this invention, aconductive terminal 24, best seen in FIG. 4, is utilized in terminatingthe antenna wires 20 so that the antenna wires may be connected to theradio receiver of the automotive vehicle. In greater detail, thepreferred conductive terminal 24 is formed from a brass plate, the platethereafter having a coat of tin placed thereover.

In accordance with the method of this invention, the conducive terminal24 is formed so as to have a first end portion 26 in the shape ofprojecting neck and a second end portion 28 in the shape of a connectortip. Between the first end portion and the second end portion, there isformed a main body portion 30 of the conductive terminal.

As best seen in FIG. 2 the conductive terminal 24 is bonded to theexposed surface of the second glass sheet 14 by utilization of a bondingmaterial 32 between the main body portion 30 of the terminal and thesurface of the glass sheet. The terminal is bonded to the glass in sucha manner that the main body portion thereof extends away from the cutoutportion 18 of the second glass sheet in a direction paralleling thedirection in which the antenna wires 20-20 extend away from the samecutout portion. By bonding the conductive terminal to the glass sheet,any forces applied to the conductive terminal are transferred to theglass sheet rather than to the junction which is formed between theterminals and portion or projecting neck 26 and the free ends of thefine antenna wires. The bonding material utilized to bind the terminalto the glass may be any material such as an adhesive or other suitablebonding agent.

In a preferred way of bonding the terminal 24 to the exposed surface ofthe second glass sheet 14, polyvinyl butyral material is utilized as thebonding agent. This material is the same material which is preferred forutilization as the laminating interlayer between the glass sheets. Asmall strip of polyvinyl butyral is placed between the body portion 30of the terminal 24 and the exposed surface of the second glass sheet.Thereafter a clip or other suitable clamping device is placed over theterminal and the glass sheets so that the terminal is held against thebonding material may then be subjected to heat and pressure in anautoclaving operation in order to form the final bond between theterminal and the glass. In a preferred method, the autoclaving step tobond the terminal to the glass sheets may be carried out at the sametime as the glass sheets are autoclaved in order to cure the interlayerdisposed therebetween and cause the lamination of the two glass sheets.

Once the conductive terminal 24 has been bonded to the exposed surfaceof the second glass sheet 14, the free ends of the antenna wires 20--20projecting outwardly into the cutout portion 18 of the second glasssheet, can be terminated to the first end portion 26 of the terminal.The termination is accomplished by taking an individual free end of oneof the antenna wires 20 and wrapping it at least one turn about theprojecting neck of the first end portion of the terminal. If the antennawire has a coating of paint or othermaterial thereon for the purpose ofprotecting the same, it is necessary to remove the paint or othermaterial to obtain a proper termination of the antenna wires to theconductive terminal. The removal of such material may be accomplished byapplying fine sandpaper to the free ends of the wires.

Once both of the antenna wires 20-20 have been connected to the firstend portion 26 of the terminal 24, the terminals first end portion isdeformed into the space left vacant by the cutout portion 18 of thesecond glass sheet 14. A small amount of solder 33 (FIG. 2) is appliedto the antenna wires and the projecting neck for the purpose of insuringa proper quality electrical junction being formed therebetween. Anyexcess antenna wire remaining after a portion of the antenna wire hasbeen soldered may be clipped ofi'.

Upon completion of the soldering operation, a scaling compound 34, suchas shown in FIGS. 2 and 3, is flowed into the space left vacant by thecutout portion 18 of the glass sheet 14. The sealing material orcompound is flowed by any suitable means, for example, through apressurized nozzle arrangement to fill the space as aforedescribed. Asuitable compound may be formed from a material such as silicone rubberbase adhesive. This type of sealing material does fairly rapidly andonce it is dried, the material forms a barrier which is impervious tomoisture and other types of detrimental material which could ruin theelectrical characteristics of the antenna wire junction.

As best understood by reference to FIGS. 3 and 4, the second end portionor connector tip 28 of the conductive terminal 24 is bent away from theplane of the body portion 30 of the terminal in a direction away fromthe exposed surface of the second glass sheet 14. This portion of theconductive terminal is formed so as to be matable with a femaleelectrical connector 36 of standard construction, as best seen in FIG.3. The female electrical connector is both supported by various bodypanels 38-40 of an automotive vehicle and connected to the radio (notshown) carried within the vehicle.

As may best be understood by reference to FIG. 2, the main body portion30 of the conductive terminal 24 can be protected, if desired, byplacing a sealing and protecting material 42 thereover. The material 42is shown only in FIG. 2 and may be a material such as an electricalinsulating tape. This insulating tape is optional, but its use ispreferred so as to protect the electrical terminal over the greatestextent of its body portion from being attacked by elements which wouldeither ruin or destroy the same.

Thus, there has been described herein a preferred method formanufacturing a windshield antenna system in which any pulling forceapplied to the electrical connector which connects the antenna wires ofthe system to the radio receiver of the vehicle is dissipated as a forceapplied to the glass by the terminal. By applying the force in such amanner rather than directly to the junction formed between the terminaland the fine wires, the junction is protected from damage.

We claim:

I. A method of terminating free end portions of antenna wires which areadhered for most of their length to a resinous interlayer materialbonding two glass sheets together to form a windshield, the free endportions of the wires being exposed in a cutout portion of one of theglass sheets, which method comprises the steps of: bonding said antennawires to said resinous interlayer material; forming a pair of glasssheets. one of said glass sheets having a cutout portion at a centrallocation along a lower edge thereof; uniting said resinous interlayermaterial to said glass sheets with free end portions of said antennawires extending into and being exposed in said cutout portion of saidone glass sheet;

forming a conductive metal terminal having a first end portion defininga projecting neck, a main body portion and a second end portion defininga connector tip;

bonding at least a portion of said body portion of said terminal to theouter exposed surface of said one glass sheet with said first endportion of said terminal defining said projecting neck extending to aposition which is located over said cutout portion of said one glasssheet;

wrapping at least a portion of each of said free ends of the antennawires around said first end portion defining said projecting neck ofsaid terminal;

deforming said wrapped wires and said said terminal into the space tionof said one glass sheet;

forming an electrical junction between the wrapped antenna wires andsaid terminal, and

cutting off any extraneous antenna wire around said projecting neck.

2. The method of terminating the antenna wires of a windshield antennaas defined in claim 1 further comprising the step of: sealing the spaceinto which said projecting neck projecting neck of provided by saidcutout pornot wrapped of said tenninal and the wrapped antenna wires arelocated after being deformed.

3. The method of terminating a windshield antenna as defined in claim 2further comprising the step of: sealing and insulating the main bodyportion of said tenninal which is bonded to the exposed surface of theone glass sheet.

4. The method of terminating a windshield antenna as defined in claim 3further comprising the step of: deforming said second end of saidtenninal defining a connector tip away from the plane of said main bodyportion of said terminal in a direction away from the exposed surface ofthe second glass sheet.

5. The method of tenninating a windshield antenna as defined in claim 1wherein said bonding step is carried out by: positioning a piece ofpolyvinyl butyral between the body por tion of said terminal and saidsecond glass sheet, clamping said terminal to said glass sheet, andautoclaving said clamped terminal and the second glass sheet wherebyheat and pressure are applied to said terminal and the glass sheet.

2. The method of terminating the antenna wires of a windshield antennaas defined in claim 1 further comprising the step of: sealing the spaceiNto which said projecting neck of said terminal and the wrapped antennawires are located after being deformed.
 3. The method of terminating awindshield antenna as defined in claim 2 further comprising the step of:sealing and insulating the main body portion of said terminal which isbonded to the exposed surface of the one glass sheet.
 4. The method ofterminating a windshield antenna as defined in claim 3 furthercomprising the step of: deforming said second end of said terminaldefining a connector tip away from the plane of said main body portionof said terminal in a direction away from the exposed surface of thesecond glass sheet.
 5. The method of terminating a windshield antenna asdefined in claim 1 wherein said bonding step is carried out by:positioning a piece of polyvinyl butyral between the body portion ofsaid terminal and said second glass sheet, clamping said terminal tosaid glass sheet, and autoclaving said clamped terminal and the secondglass sheet whereby heat and pressure are applied to said terminal andthe glass sheet.